Table 6.
Sensitivity, specificity, and multivariate logistic regression for prediction of influenza versus dengue and influenza versus other febrile illnesses
| Influenza n/N (%) | Dengue n/N (%) | Other febrile illnesses n/N (%) | Adjusted odds ratio | 95% CI | P | Sensitivity% | Specificity% | |
|---|---|---|---|---|---|---|---|---|
| Influenza vs. dengue | ||||||||
| All ages | ||||||||
| No skin rashes | 234/238 (98.3) | 58/145 (40) | - | 131.336 | 35.416-487.039 | <0.001 | 98.3 | 60 |
| No leukopeniaa | 225/232 (96.9) | 64/145 (44.1) | - | 24.978 | 7.010-89.006 | <0.001 | 96.9 | 55.9 |
| No marked thrombocytopeniab | 233/238 (97.9) | 37/145 (25.5) | - | 105.973 | 31.687-354.419 | <0.001 | 97.9 | 74.5 |
| Age ≤18 years | ||||||||
| No skin rashes | 185/189 (97.9) | 12/23 (52.2) | - | 326.393 | 30.860-3452.098 | <0.001 | 97.9 | 52.2 |
| No leukopeniaa | 185/189 (97.9) | 9/23 (39.1) | - | 122.116 | 10.888-1369.665 | <0.001 | 97.9 | 60.9 |
| No marked thrombocytopeniab | 186/189 (98.4) | 11/23 (47.8) | - | 88.632 | 6.443-1219.174 | 0.001 | 98.4 | 52.2 |
| Age >18 years | ||||||||
| No leukopeniaa | 46/49 (93.9) | 55/122 (45.1) | - | 13.99 | 3.628-53.946 | <0.001 | 93.9 | 54.9 |
| No marked thrombocytopeniab | 45/49 (91.8) | 26/122 (21.3) | - | 34.096 | 10.622-109.445 | <0.001 | 91.8 | 78.7 |
| Influenza vs. other febrile illnesses | ||||||||
| All ages | ||||||||
| Rhinorrhea | 152/238 (63.9) | - | 57/137 (41.6) | 3.350 | 1.997-5.618 | <0.001 | 63.9 | 58.4 |
| Malaise | 105/238 (44.1) | - | 16/137 (11.7) | 6.050 | 3.207-11.414 | <0.001 | 44.1 | 88.3 |
| Sore throat | 105/238 (44.1) | - | 30/137 (21.9) | 3.407 | 1.960-5.922 | <0.001 | 44.1 | 78.1 |
| Dyspnea | 41/238 (17.3) | - | 1/137 (0.7) | 47.335 | 6.174-632.919 | <0.001 | 17.3 | 99.3 |
| Mild thrombocytopeniac | 38/238 (15.9) | - | 5/137 (3.6) | 3.779 | 1.309-10.908 | 0.014 | 15.9 | 96.4 |
| Age ≤18 years | ||||||||
| Rhinorrhea | 131/189 (69.3) | - | 53/106 (50) | 2.765 | 1.531-4.997 | 0.001 | 69.3 | 50 |
| Malaise | 76/189 (40.2) | - | 6/106 (5.7) | 11.129 | 4.455-27.802 | <0.001 | 40.2 | 94.3 |
| Sore throat | 83/189 (43.9) | - | 21/106 (19.8) | 3.575 | 1.892-6.753 | <0.001 | 43.9 | 80.2 |
| Dyspnea | 24/189 (12.7) | - | 1/106 (0.9) | 20.867 | 2.641-164.872 | 0.004 | 12.7 | 99 |
| Mild thrombocytopeniac | 24/189 (12.7) | - | 2/106 (1.9) | 7.138 | 1.509-33.769 | 0.013 | 12.7 | 98.1 |
| Age >18 years | - | |||||||
| Rhinorrhea | 36/81 (44.4) | - | 8/45 (17.8) | 4.726 | 1.654-13.5 | 0.004 | 44.4 | 82.2 |
| Malaise | 42/81 (51.9) | - | 13/45 (28.9) | 3.108 | 1.224-7.897 | 0.017 | 51.9 | 71.1 |
n/N = number of patients/total number of patients with data available; CI = confidence interval.
aLeukopenia is defined as white cell counts <3.0 × 109 cells/L.
bMarked thrombocytopenia is defined as platelet counts <100 × 109 cells/L.
cMild thrombocytopenia is defined as platelet counts 149-100 × 109 cells/L.